The present disclosure relates to medical devices. More particularly, the invention relates to an intraluminal support device having a region which produces a high radial force (HRF) and a region which produces a low radial force (LRF) for treating a vascular malady such as a compressive lesion.
Intraluminal support devices, such as stents, are used to maintain the patency of blood vessels. As part of the common practice of using self-expanding intraluminal support devices, the device is deployed with a set size mismatch. The device has a larger diameter than the natural diameter of the target vessel. Such a mismatch functions to prevent migration of the device through the vasculature and to supply a radial force against the vessel wall.
An excessive amount of radial force, however, can have a negative effect and lead to increased late lumen loss. As stretch receptors are triggered by chronic radial force, the vessel wall thickens inward to equalize the force supplied by the implant. In some aspects, such thickening may be intimal hyperplasia. Such vessel wall thickening can also be seen in conditions of venous hypertension, as pressure increases activate the same physiological mechanisms. As such, the use of large high radial force for treating compressive lesions, such as May-Thurner Syndrome or compressive tumors, is a challenge, as high enough radial force to maintain vessel patency must be balanced against low enough levels of radial force to prevent or slow remodeling. Moreover, vessels with stenosis may require treatment with such an intraluminal support device in order to increase outflow from the deep venous system as part of a treatment regimen for chronic venous insufficiency (CVI).
There is a need for improved intraluminal support devices which produce high enough radial force to remain in place in the vasculature and maintain vessel patency without triggering vessel remodeling due to the production of a chronic high radial force.